Yet another DS1307 Real-Time Clock library for Arduino
C++ Processing
Fetching latest commit…
Cannot retrieve the latest commit at this time.

My goal in creating yet another DS1307 library was to provide easy access to some of the other functions I needed from the chip, specifically its square wave output and its battery-backed RAM.


@todo Mostly comments in RealTimeClockDS1307.h

Examples (in /examples folder)

  • RealTimeClockDS1307_Test.pde allow you to turn the clock on/off, set date/time, set 12/24h, [de]activate the square wave, and read/write memory from the Serial Monitor.

  • RealTimeClockDS1307.fz is a Fritzing breadboard layout showing the basic hookup of the Sparkfun RTC module to an Arduino. Included is an optional resistor+LED to show the square wave (note that it's an open drain, so you hook up to it rather differently than, say, pin 13).


Version 0.95
  • Reverse renaming of getDate() and setDate(), now getDay() is calling getDate() and setDay() is calling setDate()
  • Readme improvements
Version 0.94
  • changed getDate() to getDay() and setDate() to setDay()
  • updated keywords.txt
  • updated example
Version 0.93
  • added keywords.txt for syntax highlighting
Version 0.92 RC
  • Updated for Arduino 1.00; testing with Andreas Giemza (hurik)
Version 0.91
  • added multi-byte read/write
Version 0.9 RC
  • initial release


  • web page documentation


Much thanks to John Waters and Maurice Ribble for their earlier and very helpful work (even if I didn't wind up using any of their code):


RealTimeClockDS1307 - library to control a DS1307 RTC module Copyright (c) 2011 David H. Brown. All rights reserved


This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA